To improve upon the construction of truck bed members which are formed using a conventional stamping process, the assignee of this application developed the improved truck bed structures and forming methods disclosed in U.S. Pat. Nos. 5,188,418, 5,544,932, 5,575,525, 5,730,486, 5,938,272, 6,128,815, 6,170,905, 6,286,352, 6,347,454 B1, 6,799,792 B2 and all of which are assigned to Pullman Industries, Inc., and are herein incorporated by reference.
In the aforesaid patents, and the exemplary bed assembly illustrated in FIG. 1, there is disclosed a main floor pan or bed member 11 which was developed principally for a conventional duty pick-up truck so that the bed member 11 is disposed between the side walls 12 of the truck and extends rearwardly from the front wall 13 so as to terminate at the rear sill 14. The bed member has the rear edge thereof secured, typically by welding, to the rear sill 14, and the bed member is typically supported on and fixedly secured to additional cross sills which are spaced longitudinally along the bed, such as the intermediate cross sills 15 and the front sill 16. The bed member 11 is roll formed from a continuous sheet of thin steel so as to have alternating ribs 18 and valleys 19 of channel-like cross-section disposed sidewardly thereacross with such ribs and valleys extending longitudinally along the roll formed sheet. The roll formed sheet is then cut to length to define the bed member.
In the illustrated bed member 11, the bed member 11 has the front and rear edges thereof having a corrugated configuration defined by the alternating ribs and valleys. In a preferred variation of this bed construction, the rear sill 14 is provided with protruding projections 17 on the top wall thereof, which projections interfit within the channels of the bed member 11 at the rear edge thereof to provide for a strong structural assembly while also closing off the rear ends of the ribs.
The arrangement described above and as briefly illustrated in FIG. 1 has proven to provide a highly desirable bed assembly for many applications. However, the projections 17 are conventionally stamped, which may be difficult to accomplish for heavy-duty applications using high-strength steel.
In a continuing effort to provide for and accommodate other demands associated with the use of pickup-type vehicles, the assignee hereof has also developed a modified end construction for the bed member 11 which, as illustrated by FIGS. 2-5, results in the ends of the ribs 18 being flattened downwardly through a tapered or downwardly sloped rib section so as to merge with the bottom of the bed member, namely the walls which define the bottoms of the valleys, so as to effect closure of the ends of the ribs and at the same time result in the edge of the bed member being generally flat.
As disclosed in U.S. Pat. No. 6,347,454 B1 which is incorporated herein by reference, the construction illustrated by FIGS. 2-5 results in a modified edge construction for the roll-formed bed member 11 so as to permit the edge portion of the bed to be supported on a conventional cross sill 21 (which can be either a rear sill or a front sill) without the necessity of providing the top wall of the sill with upward projections for nesting within the channels of the ribs, although provision of such projections on the cross sill is still a preferred alternative. In this edge construction, the bed member 11 is provided with a flat and substantially planar flange 22 extending transversely across the bed member, which flange terminates at a free edge 23 of the bed member. The flange 22 is defined by deforming and hence flattening rear portions of the channel-like ribs 18 over a selected longitudinal length which projects forwardly from the free edge 23.
The bed member 11 of FIGS. 2-4 in addition has the ribs 18 thereof, just forwardly of the flange 22, downwardly deformed to define tapered rib portions 18A which extend longitudinally of the bed member over a small longitudinal distance, and define a transitional zone between the rear flange 22 and the longitudinally-extending full-height rib 18. The tapered rib portions 18A each have a top wall 25A which at one end is continuous with and joins to the top wall 25 of the full-height rib 18, with the top wall 25A then angling or sloping downwardly as it projects longitudinally until intersecting the plane of the bed member base walls 26 (the latter defining the bottom of the valleys 19), which intersection substantially defines the transition between the tapered rib portions 18A and the rear flange 22. The tapered rib portions 18A thus effectively define a slope or ramp which projects upwardly from the elevation of the base walls 26 or flange 22 to the elevation of the rib top walls 25, with the ramp projecting in a longitudinal direction which, when the tapered rib portion is at the rear edge of the bed member, slopes upwardly in the forward direction of the bed member to thus eliminate or minimize any abrupt or sharp corners at the rear edge of the bed member.
The tapered rib portions 18A are shaped by physically deforming a selected length of the full-height ribs 18 downwardly into the tapered or sloped configuration, which forming typically is carried out in a shaping press following the roll forming of the bed member. The deforming (i.e. compressing) of the ribs 18 into the tapered configuration results in at least partial collapsing of the side walls 27 of the ribs, and the tapered rib portion 18A is preferably formed so that the top wall 25A thereof extends at a slope or angle relative to the horizontal of at least about 30°, and more preferably in the neighborhood of about 40° to about 45°, in an effort to minimize the amount of material which is being physically displaced during the compression of the ribs into the tapered shape.
During the deforming of the end portions of the ribs 18 so as to form the tapered rib portions 18A, the end portions of the ribs 18 which extend between the tapered portions 18A and the rear edge 23 are also substantially simultaneously flattened during the same deforming or pressing operation so that the rib portions which extend throughout the longitudinal length of the flange 22 are effectively flattened so as to be substantially coplanar with the base walls 26 and thereby result in the substantially flat and planar edge flange 22.
With the arrangement as illustrated by FIG. 2, the flange 22 can be positioned so as to lie flatly on an upper surface of the cross sill so as to permit closure and fixed securement therewith.
Alternatively, the flattened rear flange, designated 22A in FIG. 5, can be bent downwardly in the vicinity adjacent or slightly rearwardly from the intersection point with the tapered rib-portions 18A, which flange 22A can be disposed so as to project downwardly directly adjacent and hence overlap a side surface of the supporting cross sill 21, such as the rear surface when the cross sill 21 constitutes the rear sill of the vehicle bed construction. In this arrangement the flange 22A can be fixedly secured to the cross sill, such as by welding.
While the rib end constructions illustrated by FIGS. 2-5 may be desirable for some use situations, nevertheless these rib end constructions created by reforming a roll-formed bed member result in undesired wrinkling of the material during the deforming or flattening operation. In order to deform the full-height rib into either the tapered rib portion and/or the flat rear flange, it is necessary to cause the excess material which exists due to the presence of the side walls 27 to be redistributed so as to merge into the material associated with the adjacent top or bottom walls 25 and 26. Because of this excess material, stamping of the rear ends of the ribs is normally unable to effectively redistribute this excess material, and hence the tapered rib portions 18A particularly in the vicinity of the sides thereof, and particularly the flat rear flange 22 in the vicinity where the side walls 27 previously existed, often exhibit significant wrinkling due to the excess material so that the resulting wall structure not only loses its desired uniformity of thickness but also results in undesired surface characteristics which may be considered unacceptable, particularly when painting or the like.
Accordingly, in a continuing effort to improve the construction of bed members formed initially by roll forming, and which are then subjected to further forming such as pressing so as to define tapered end configurations similar to those depicted by FIGS. 2-5, another improved tapered rib end configuration and forming process has been developed which permits end portions of the roll-formed ribs to be subsequently deformed, as by stamping, and which construction and process eliminates or at least greatly minimizes undesired wrinkling by permitting more effective redistribution of excess material during the deforming operation, and which in addition provides the resulting tapered rib portion with increased strength and rigidity. This further construction is disclosed in U.S. Pat. No. 6,799,792 B2 and further illustrated in FIGS. 6-10 hereof.
Referring to FIG. 6, there is illustrated a portion of a vehicle bed member 11 which is of an integral one-piece construction formed by longitudinally roll forming a thin metal sheet such that the sheet initially has downwardly-opening channel-like ribs 18 extending longitudinally in sidewardly spaced but parallel relationship, with these ribs being sidewardly spaced by intermediate valleys 19. The ribs 18 are provided with a flat flange 31 along at least one transverse end edge thereof, which flange joins to the ribs 18, with the latter having tapered rib end portions 32 associated therewith similar to the arrangements of FIGS. 2-5 except that the tapered rib portions 32 and the flange 31 are both shaped so as to compensate for the excess material which exists during flattening of the ends 35 of the ribs 18 to thus eliminate or at least greatly minimize the presence of wrinkles either in the tapered rib end portion 32 or in the end flange 31.
The top wall of the tapered rib portion 32 is offset downwardly relative to the top and side edges thereof so as to define a shallow downwardly-offset recess 33, and the flange 31 where it merges with the tapered rib portion is, over a selected longitudinal extent of the flange 31, offset upwardly so as to define a recess 34. These recesses 33 and 34 are substantially simultaneously formed during flattening or deforming of the rib end portion, which flattening basically involves that portion of the rib which extends to the free end of the bed member, substantially as diagrammatically depicted by dotted lines 35 in FIG. 7.
With respect to the construction of the tapered rib portion 32, this portion longitudinally merges with the top wall 25 of the rib 18 such that, during the deforming of the rib end portion 35, the top wall 25 at its juncture to the tapered rib portion 32 is bent downwardly through a substantially reverse bend, i.e., a shallow S-curve bend 36, for merger with a generally flat but downwardly sloped end wall 37 of the tapered rib portion 32. This substantially flat end wall 37 extends transversely (i.e., sidewardly) between raised edge portions 38 which slope downwardly from their juncture with the top rib wall 25 in parallel relation to the top sloped wall 37. The edge portions 38 extend generally along the side walls 27 of the rib for merger with the flat and planar flange 31 at a location spaced longitudinally from the free edge 39 of the flange. The edge portions 38 effectively protrude upwardly above the tapered end wall 37 so as to define the downward offset recess 33 therebetween. The projections 38 are of a generally upwardly rounded arcuate shape so as to provide a continuous merger between the end wall 37 and the rib side walls 27. Due to the provision of the recess 33 and the downward offset of the tapered end wall 37 created thereby, this results in the formation of the arcuate projections 38 which have a generally downwardly-opening channel or U-shaped configuration so that these projections hence require additional material to form, and thus compensate for the excess material created during the deformation process.
During the forming of the tapered rib portion 32 as discussed above, the deformation of the rib end portion 35 also results in simultaneous formation of the flat edge flange 31, and the latter is also additionally and substantially simultaneously deformed so as to create therein the recess 34 which in effect results in formation of a raised wall or platform 41 which joins to the lower edge of the tapered top wall 37 and which projects longitudinally outwardly of the flange 31 so as to terminate at a rear edge 42 which is still spaced longitudinally from the free edge 39. This platform 41 as illustrated preferably has a width which approximately corresponds to the spacing between the raised side protrusions 38 adjacent the lower ends thereof where these protrusions merge into the flange 31. The raised wall or platform 41 is preferably generally flat or planar, and is generally parallel with but raised upwardly from the flange 31, with the side edges 43 of the platform 41 generally being disposed so as to merge in with the lower side edges of the tapered top wall 37.
The creation of the platform 41 accordingly results in the formation of the edge walls 42 and 43 which extend generally vertically and join the raised platform 41 to the flange 31, whereby these edge walls 42 and 43 hence require additional material to permit formation thereof. These walls 42, 43 are thus formed using much of the excess material which is created during flattening of the rib end portion 35.
Despite these improvements as described above, it is an object of the invention to provide a further improved vehicle bed member, preferably formed substantially through roll-forming which is usable with conventional duty vehicles and is particularly suitable for heavy-duty applications using high-strength steel. The invention therefor relates to an improved bed assembly having a panel-like bed member which preferably is roll-formed so as to have the aforementioned ribs and valleys formed therein. The invention relates to this bed member which is further improved so as to cooperate with a high-strength rear sill member in a manner which has an increased structural rigidity and strength and greater weld capability for welding the bed member to a sill and preferably at least to the rear sill.
In this bed member, the bed member is initially roll-formed so as to be formed with longitudinally extending channel-like ribs and sidewardly spaced but parallel valleys. Along the rear edge of the bed member, the bed member is subsequently shaped after roll-forming so as to form an elongate channel extending centrally along the middle of each rib between opposite rib walls, which channel has a bottom channel wall that extends in the bottom plane of the bed member for direct facing, contacting engagement with an upper surface of the rear sill to not only provide additional support to the rear edge of the bed member, but also define a weld location located within the width of the rib. As described in further detail herein, this improved bed member with end channels being formed centrally within each rib results in an improved, high-strength connection between the rear sill and an increased contact area and quantity of weld areas to generate a stronger connection that accommodates increased bed loads.
With the improved bed member of this invention, the one-piece roll-formed bed member can be formed generally to occupy only the center portion of the truck bed, namely that portion which extends between the wheel wells of the vehicle, or in the alternative the one-piece bed member may be formed so as to define the entire truck bed width by having the wheel wells cut therefrom. Both of these variations are disclosed in the assignee's earlier patents, identified above, and are encompassed within the present invention. Further, while the rib construction of this invention is particularly desirable for use at the rear edge of the bed member for cooperation with the rear sill of the vehicle, it will be appreciated that the improved rib construction of this invention is equally applicable for use at the front end of the bed member, either by itself or in conjunction with use of the same or a similar rib construction at the rear end of the bed member.
With the improved interconnection between the bed and sill, higher strength steel and higher-load capacity sills may be used since roll-forming is the primary process used to form the sill and bed member and is better able to accommodate the high-strength steel.
Other objects and purposes of the invention, and variations thereof, will be apparent upon reading the following specification and inspecting the accompanying drawings.
Certain terminology will be used in the following descriptions for convenience and reference only, and will not be limiting. For example, the words “upwardly”, “downwardly”, “rightwardly” and “leftwardly” will refer to directions in the drawings to which reference is made. The words “inwardly” and “outwardly” will refer to directions toward and away from, respectively, the geometric center of the bed member and designated parts thereof. Said terminology will include the words specifically mentioned, derivatives thereof, and words of similar import.